This question has been asked by the FAA, the federal aviation agency that regulates private launches in the United States: Space debris that falls to Earth and resists re-entry into the atmosphere will become more and more numerous. Therefore, the risk of collision with the plane will be higher. SpaceX is challenging the conclusions about this deadly risk. Futura is evaluating the matter with Pierre Umali, a space debris expert at CNES.
This will interest you too
This is another alarming report on the state of space debris. We have long known that their numbers will continue to increase. For your information, the European Space Agency (ESA) has cataloged more than 36,500 pieces of debris larger than ten centimeters in low orbit, and estimates that there are approximately one million pieces between one centimeter and ten centimeters in size.
The problem has so far been an exceptional incident
Posted on September 22, FAA report (Federal Aviation Administration) Today warns of the disintegration of debris and satellites that have fallen out of orbit in our atmosphere. Due to its speed, its penetration into the air causes such strong friction that disintegration is almost complete. barely. A few pieces of debris managed to survive the passage and fell back into our lower atmosphere, and then to Earth. We are generally concerned when it comes to large structures penetrating our atmosphere. For example, we remember well the uncontrolled reentry of the first stage of a Chinese rocket Long March 5 Which led to the precautionary closure of a number of airspaces in southern Europe. but As he pointed out According to the European Space Agency, the number of debris returning to our atmosphere is actually increasing.
0.84% chance of impact in 2035
Fortunately, most of the debris that passes through our atmosphere has a high chance of falling back into the seas or oceans. But as with the example Long March 5Crossing it may lead to the closure of the airspace to avoid any risk of collision, no matter how small.
According to the report, the risk of a collision between an aircraft and debris passing through the lower atmosphere, currently estimated at 0.01%, will rise to 0.84% in 2035. A sharp increase that should not be taken lightly, but is it realistic? ” The report was initially written by Aerospace Corporation, a company that is highly proficient in solving the debris re-entry problem and has long-standing experience », determined by Futura Pierre Umali, expert in space debris at CNES.
The reason mentioned is the current and future increase in the number of satellites disintegrating in the atmosphere. Recently, SpaceX Put 5000 into orbitH Satellite, while Amazon has just deployed the first two flagship satellites from the massive Kuiper constellation of more than 3,400 satellites.
SpaceX’s counterargument
Is the FAA report based on outdated technology? Pierre Umali explains to Futura: “ This report is based on extrapolations about the situation as we know it today. They took what they knew back into the atmosphere, things they had already seen. And the things on the ground are not many. There is in particular the case of Iridium satellites [constellation de communication, NDLR]We know that when the satellite returns, a tank reaches Earth. They started from this hypothesis, assuming that all satellites were like that, because that’s the only realistic data we have today, and then they established rules of three: “.
This supposedly incomplete breakup is disputed by SpaceX In a message Directed at the US government, it claims that Starlink satellites are designed to completely disintegrate in the atmosphere, without producing any debris. Starlink program lead engineer David B. Goldstein says none of the 325 Starlink deorbits performed since February 2020 have produced debris. ” We can only take their word for it because we do not have access to their documents, Pierre O’Malley identifies. It’s still possible but I’m curious what solutions they used because it’s a real challenge. »
The report describes the rate of controlled re-entry of satellites into the atmosphere as approximately 90%, and SpaceX claims it is 99%. Another argument from SpaceX: In the report, the estimated number of satellites in orbit in 2035 takes into account the full deployment of 30,000 Starlinks, while the number allowed today by the FCCFederal Communications Commission) is 7518. It is a strange argument considering that SpaceX intends to deploy 30,000 satellites. In addition, last week, SpaceX provided From the International Telecommunication Union (ITU, United Nations branch), a request to use frequencies… for 29,988 satellites!
In terms of organization?
With OneWeb, Kuiper, or even China’s mega-constellation projects, the number of satellites in low orbit would be prohibitive. Will they all completely disintegrate in the atmosphere? However, on the French side, it will soon be imposed, as Pierre Umali reminds us: “ In the development of the Space Operations Act (scheduled for release in early 2024), this issue will be written specifically. It would be required that the total risk of the constellation to the population is not greater than 0.0001%. The entire constellation must be completely destroyed during re-entry into the atmosphere. “.
